Professor of Astronomy, Harvard University; Director, Harvard Origins of Life Initiative; Author, The Life of Super-Earths

The Other

The concept of 'otherness' or 'the Other' is about how a conscious human being perceives their own identity: "Who am I and how do I relate to others?"; a part of what defines the self and is constituent in self-consciousness. It is a philosophical concept widely used in psychology and social science. Recent advances in the life and physical sciences have opened the possibility for new and even unexpected expansions of this concept.

Starting with the map of the human genome, to the diploid human genomes of individuals, and to mapping humans' geographic spread, then moving back in time with the mapping of the Neanderthal genome, these are new tools to address the age-old problem of human unity and human diversity. Reading the 'life code' of DNA does not stop here – it places humans in the vast and colorful mosaic of Earth life. 'Otherness' is placed in totally new light. Our microbiomes – the trillions of microbes on and in each of us, that are essential to a person's physiology, become part of our self.

Astronomy and space science are intensifying the search for life on other planets – from Mars and the outer reaches of the Solar system, to Earth-like planets and super-Earths orbiting other stars. The chances of success may hinge on our understanding of the possible diversity of the chemical basis of life itself. 'Otherness': not among DNA-encoded species, but among life forms using different molecules to encode traits. Our 4-billion-years-old heritage of molecular innovation and design, versus 'theirs'. This is a cosmic first encounter that we might experience in our labs first. Last year's glimpse at JCVI-syn1.0 – the first bacteria controlled completely by a synthetic genome, is a prelude to this brave new field.

It is probably timely to ponder 'otherness' and its wider meaning yet again, as we embark on a new age of exploration. And as T.S. Eliot once predicted, we might arrive where we started and know our self for the first time.